Crazy dream about nuclear war: Would I have survived it?

I had a dream in which I was part of a group of people who built a bomb shelter for an impending nuclear attack-a big one, that was below ground by a good 50 feet or more, and shielded with fallout and radiation resistant concrete walls. We were situated something akin to 40-50 miles from a city that was a nuclear target. As the nuclear attack was inbound, I raced up top to help a person in our group who needed help downstairs because he had been in a car accident-I was about the only one with the courage to do so. As we were getting to the entrace-which was protected on the city side by similar blast and radiation proof walls-there was a bright flash. I still got downstairs, and there was no shockwave or blast that I felt. Would I have lived through this?